西安市与上海市婴儿感染百日咳鲍特菌基因型比较

Genotypes of Bordetella pertussis isolated from infants in Xi’an and Shanghai

目的:探讨西安市与上海市临床分离百日咳鲍特菌的基因型特征。方法:收集2018—2019年在西安市和上海市哨点监测医院和社区采集的1岁以下疑似百日咳患儿的鼻咽拭子,经分离培养所得百日咳鲍特菌采用多位点抗原序列分型(MAST)和多位点可变数目串联重复序列分析(MLVA)方法分析其基因型。结果:共采集到疑似百日咳患儿鼻咽拭子1200份,经分离培养得到百日咳鲍特菌60株,其中西安市34株,上海市26株。西安市百日咳鲍特菌的主要MAST型别为prn1/ptxP1/ptxA1/fim3-1/fim2-1(32/34,94.12%),而上海市百日咳鲍特菌的主要MAST型别为prn1/ptxP1/ptxA1/fim3-1/fim2-1(13/26,50.00%)和prn2/ptxP3/ptxA1/fim3-1/fim2-1(11/26,42.31%),两市百日咳鲍特菌MAST型别分布差异有统计学意义(χ2=18.642,P<0.01)。西安市百日咳鲍特菌以MT195(13/34,38.24%)、MT55(10/34,29.41%)、MT104(9/34,26.47%)型别居多,而上海市百日咳鲍特菌以MT27型为主(12/26,46.15%),两市百日咳鲍特菌MLVA型别分布差异有统计学意义(χ2=15.866,P<0.01)。结论:西安市与上海市临床分离婴儿感染百日咳鲍特菌基因型存在差异,应进一步加强中国百日咳鲍特菌基因型演变的监测。

Objective:To compare the genotypes ofBordetella pertussisisolated from infants in Xi’an and Shanghai.Methods:Samples were collected by nasopharyngeal swab from infants aged <1 year hospitalized with suspected pertussis in Xi’an and Shanghai during 2018 and 2019.Bordetella pertussiswas isolated,and multilocus antigen sequence typing(MAST) and multilocus variable-number tandem repeat analysis(MLVA) were used to analyse the genotypes.Results:A total of 1200 samples were collected from infants suspected of pertussis and 60 strains ofBordetella pertussiswere isolated,including 34 strains in Xi’an and 26 strains in Shanghai.There were significant differences in the MAST types between Xi’an and Shanghai(χ^(2)=18.642,P<0.01);theprn1/ptxP1/ptxA1/fim3-1/fim2-1strains dominated in Xi’an(32/34,94.12%),while the dominated MAST types in Shanghai wereprn1/ptxP1/ptxA1/fim3-1/fim2-1(13/26,50.00%) andprn2/ptxP3/ptxA1/fim3-1/fim2-1(11/26,42.31%).The composition of MLVA type of pertussis strains was also significantly different between Xi’an and Shanghai(χ2=15.866,P<0.01);the MT195(13/34,38.24%),MT55(10/34,29.41%) and MT104(9/34,26.47%) strains dominated in Xi’an,while the MT27(12/26,46.15%) strain was most common in Shanghai.Conclusion:There are differences in molecular types ofBordetella pertussis isolated from infants with suspected persussis in Xi’an and Shanghai,indicating that further monitoring ofBordetella pertussisis necessary for better understanding the pathogen evolution in China.